Deposition of calcium phosphate coating on nanotubular anodized titanium

Nanotubular anodic oxide layer was grown on titanium surface by room temperature anodization in 0.5 M H3PO4 + 0.138 M fluoride solution. The inner surface of the nanotubular oxide walls contained adsorbed anions from the solution that were predominantly phosphate. Hydroxy apatite was electrodeposited on the anodized surface of Ti. Adsorbed phosphate ions facilitated nucleation of nanophase calcium phosphate material inside the nanotubular structure that resulted in vertical growth of apatite crystals. Bond strength of the calcium phosphate coating was found to be good, and cohesive mode of failure of the coating was observed after tensile testing.